Which of the following reactions would take place when concentrated sodium hydroxide solution is added to palm oil?

Step 1: Analyze the question Palm oil is being treated with concentrated sodium hydroxide (a strong base). We need to name the reaction.

Step 2: The concept Palm oil is a vegetable oil made of triglycerides, which are esters of glycerol (propane-1,2,3-triol) and long-chain fatty acids. When an ester is heated with a strong alkali such as NaOH, it is hydrolysed into:

• glycerol (an alcohol), and
• the sodium salt of the fatty acid, which is soap.

This alkaline hydrolysis of fats and oils is called saponification.

Step 3: The reaction

Fat/oil (triglyceride) + 3NaOH → glycerol + 3 RCOONa (soap)

This is how local soap (e.g. "black soap" or palm-oil soap) is made in Nigeria. Palm oil or palm kernel oil is mixed with a strong alkali, traditionally from potash or lye, and soap forms.

Step 4: Check the other options

• A. Esterification: This is the formation of an ester from an acid and an alcohol. It is the reverse of what happens here.
• B. Neutralization: This is an acid reacting with a base to give salt and water. Palm oil is not simply an acid, so this does not describe the process.
• C. Polymerization: This is the joining of many monomers into a long chain. It does not occur here.
• D. Saponification: This is the alkaline hydrolysis of esters (fats and oils) to give soap and glycerol. It is correct.

Step 5: Exam tip Remember "Sapo = soap". If you see a fat or oil together with NaOH or KOH, the answer is saponification. If you see an acid and an alcohol with concentrated H₂SO₄, think esterification.